Through the trees: The story of Prairie drought told by tree rings

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The Canadian Prairies are Canada’s most significant dryland area and regional drought has an enormous impact on agricultural and energy production and the reliability of public water supplies. Many water managers are turning to tree rings and other natural indicators to expand their perspective on regional hydrology.

Prepared for the Department of Geography, University of Lethbridge, April 3, 2009.

Published in: Education, Technology
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Through the trees: The story of Prairie drought told by tree rings

  1. 1. TREES THR O U G H T H E THE STORY OF PRAIRIE DROUGHT TOLD BY TREE RINGS
  2. 2. Past dynamics ! Future behavior PRESENT PAST FUTURE Precipitation Drought risks Discharge Sustainable yield Lake level Flood hazards Soil moisture
  3. 3. resource allocation
  4. 4. worst-case scenarios
  5. 5. Photograph: Manitoba Hydro
  6. 6. Photograph: Greg Brooks
  7. 7. Past dynamics ! Future behavior PRESENT PAST FUTURE Precipitation Drought risks Discharge Sustainable yield Lake level Flood hazards Soil moisture
  8. 8. stationarity A stationary time series is free of trends, shifts or periodicity, and has statistical parameters that remain constant through time.
  9. 9. Christopher Milly, Julio Betancourt, Malin Falkenmark, Robert Hirsch, Zbigniew Kundzewicz, Dennis Lettenmaier, Ronald Stouffer Stationarity is dead: whither water management? Science 319, 573-574, 2008
  10. 10. South Saskatchewan River at Saskatoon relative change in summer flow Schindler and Donahue, 2006, PNAS
  11. 11. Annual discharge since 1924 + 58% NO TREND + 52% + 46% NO TREND NO TREND NO TREND NO TREND St. George, Journal of Hydrology, 2007
  12. 12. 100 years of stream and lake gauging
  13. 13. CLIMATE HISTORY OF CANADA Younger Demise of Laurentide Dryas Ice Sheet 20 16 12 8 4 0 THOUSANDS OF YEARS AGO Final Drainage of Lake Agassiz LAST GLACIAL MODERN MAXIMUM OBSERVATIONS
  14. 14. paleoclimatology the study of the Earth’s climate prior to the period of instrumental measurements
  15. 15. TREES AS BIOLOGICAL ARCHIVES How can records from the annual growth rings of trees be 1 interpreted as indicators of past environmental change?
  16. 16. TREES AS BIOLOGICAL ARCHIVES How can records from the annual growth rings of trees be 1 interpreted as indicators of past environmental change? PRAIRIE DROUGHTS SINCE AD 1500 What tree rings tell us about severity, persistance and 2 dynamics of past droughts on the Prairies.
  17. 17. R ECO R D S F RO M ANCIEN T TR EES
  18. 18. Tree-ring display at elementary school Photograph: Tom Swetnam
  19. 19. ARIZ ONA
  20. 20. A. E. Douglass University of Arizona
  21. 21. The trees composing the forest rejoice and lament with its successes and failures and carry year by year something of its story in their annual rings. A.E. DOUGLASS
  22. 22. Same environmental forcings Similar growth patterns
  23. 23. Photograph: Howard Arnott
  24. 24. North American Tree-Ring Chronologies Western species Ponderosa pine Douglas-fir Big cone douglas-fir High elevation conifer Mountain Hemlock Other conifer Eastern species White oak group Hemlock Baldcypress Tulip poplar Overcup oak Northern red oak Courtesy David Stahle
  25. 25. MEXICO UNITED STATES Sonora Arizona Baja California California Colorado New Mexico Nevada Utah Wyoming
  26. 26. ~15 years of river gauge measurements
  27. 27. Colorado River Basin Water Management National Academy of Sciences, 2007 “... studies of past climate...[reveal] many periods when streamflow was lower than at any time in the past 100 years of recorded flows. ”
  28. 28. “rethink old assumptions” CHARLIE ESTER SALT RIVER PROJECT
  29. 29. Photograph: Tom Harlan
  30. 30. Photograph: Peter Kelly
  31. 31. Photograph: Kurt Kipfmueller
  32. 32. Photograph: Greg Pederson
  33. 33. Photograph: Erik Nielsen
  34. 34. Photograph: Erik Nielsen
  35. 35. 53 Photograph: Erik Nielsen
  36. 36. Martin-Philippe Girardin Canadian Forest Service Greg Pederson United States Geological Survey David Sauchyn Glen MacDonald Emma Watson University of Regina UCLA Environment Canada Erik Nielsen Jacques Tardif Manitoba Geological Survey University of Winnipeg
  37. 37. Prairie tree-ring network
  38. 38. T R E E S A ND PRAI RI E DR OUGHT
  39. 39. Photograph: Dave Sauchyn
  40. 40. earlywood latewood cessation of growth Photograph: Kevin Anchukaitis
  41. 41. “ The growth of trees is undoubtably controlled more by the movement of water than by the movement of any other single substance.” HAL FRITTS TREE RINGS AND CLIMATE
  42. 42. water stress narrow ring reduced photosynthesis less cell expansion reduced cell division
  43. 43. never trust one tree
  44. 44. Prairie tree-ring network
  45. 45. 2,860 trees
  46. 46. 889,862 tree rings
  47. 47. Palmer Drought Severity Index
  48. 48. 69
  49. 49. 755 m3/s 847 m3/s 809 m3/s 770 m3/s 823 m3/s 787 m3/s 901 m3/s 3
  50. 50. “This must be ” voodoo. Anonymous water manager
  51. 51. good How are drought records from tree rings?
  52. 52. geography matters
  53. 53. southern Alberta 10 3 2 5 1 Ringwidth PDSI 0 0 -1 -5 -2 -3 -10 1900 1920 1940 1960 1980 2000 Year (A.D.) St. George et al., (2009), Journal of Climate
  54. 54. southern Alberta 10 3 2 5 1 Ringwidth PDSI 0 0 -1 -5 r = 0.62 -2 -3 -10 1900 1920 1940 1960 1980 2000 Year (A.D.) St. George et al., (2009), Journal of Climate
  55. 55. 755 m3/s 847 m3/s 809 m3/s 770 m3/s 823 m3/s 787 m3/s 901 m3/s 3
  56. 56. DROUGHT HISTORY OF ALBERTA PDSI 6 4 2 0 -2 -4 -6 1500 1600 1700 1800 1900 2000 Year (AD)
  57. 57. DROUGHT HISTORY OF ALBERTA PDSI 6 4 2 0 -2 -4 -6 1500 1600 1700 1800 1900 2000 Year (AD)
  58. 58. bad How can drought get?
  59. 59. more persistent more severe
  60. 60. more persistent more severe
  61. 61. 1720s
  62. 62. 58 oN 1718 - 1722 56 oN 54 oN 52 oN 50 oN 48 oN oW 90 114 oW oW 96 o o 108 W 102 W Ringwidth anomaly (deviations) !2 !1 0 1 2 -2 0 +2
  63. 63. more persistent more severe
  64. 64. 1860s
  65. 65. 1842 to 1876 Below average Above average
  66. 66. CAPT. JOHN PALLISER 88
  67. 67. “ The grass in this arid soil, always so scanty, was now actually swept away by the buffalo, who, assisted by the locusts had left the country as bare as if it had been overrun by fire; even at the edge of Sage Creek we could obtain but very ” little water for our horses. JOHN PALLISER, 1859 89
  68. 68. Low reservoir Photograph: Glen MacDonald
  69. 69. Prairie tree-ring network
  70. 70. NUMBER of tree ring records that track seasonal precipitation Autumn Winter Spring Summer 3 7 24 82 138 total
  71. 71. Medicine Hat, Alberta Source: Environment Canada, Adjusted Historical Canadian Climate Data, 1895 – 2006
  72. 72. 96
  73. 73. Past droughts and remote forcings
  74. 74. Janice Lough and Hal Fritts The Southern Oscillation and tree rings: 1600 - 1961 Journal of Applied Meteorology 24, 1985 Roseanne D’Arrigo and Gordon Jacoby A thousand year record of northwestern New Mexico winter precipitation reconstructed from tree rings and its relation to El Niño and the Southern Oscillation The Holocene 1, 1991 David Stahle and collaborators Experimental dendroclimatic reconstruction of the Southern Oscillation Bulletin of the American Meteorological Society 79, 1998
  75. 75. ENSO and Prairie tree rings correlation with CTI St. George et al., (2009), Journal of Climate
  76. 76. INSTRUMENTAL PDSI ENSO +0.5 0 correlation coefficient -0.5
  77. 77. St. George et al., (in preparation), Geophysical Research Letters
  78. 78. LE SS ONS L E A RNED
  79. 79. WORLD DATA CENTER for PALEOCLIMATOLOGY
  80. 80. Prairie tree-ring network
  81. 81. past does the really matter?
  82. 82. climate change YOU CAN TOUCH
  83. 83. 100 years of stream and lake gauging
  84. 84. Common sense holds that what has really happened CAN HAPPEN AGAIN VIC BAKER UNIVERSITY OF ARIZONA

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